It is conventional to use a fistula catheter to administer enteral feeding whereby liquid foods or nutrients are supplied to a person who has a reduced capacity to ingest food orally due to, for example, advanced age or illness (referred to below as a “patient”). When enteral feeding is administered, a fistula is established in the patient's abdominal region (gastric fistula), the fistula catheter is fitted in the fistula, and the patient is supplied with the liquid foods through the fistula catheter.
The fistula catheters can be broadly divided into what are known as balloon-type and bumper-type fistula catheters, according to the shape of the intracorporeal fixing part placed inside the body. For example, when a balloon-type intracorporeal fixing part is fitted in a fistula, the balloon is inserted into the fistula in a narrowed, deflated configuration. A syringe can be used to inject air or physiological saline into and inflate the inserted balloon, which serves as an intracorporeal fixing part. When the balloon-type intracorporeal fixing part is to be withdrawn from the fistula, the procedure is reversed. As disclosed, for example, in JP2009-183437A, when a bumper-type intracorporeal fixing part is fitted in a fistula, the bumper is inserted into the fistula in a narrowed state of extension by using a rod-shaped extension tool. The extension tool is then removed from the bumper which has been inserted into the body, whereby the bumper is restored to its original expanded shape and is made to function as an intracorporeal fixing part. When a bumper-type intracorporeal fixing part is withdrawn, the fitting procedure is carried out in reverse.